Next time you’re strolling through one of the Outdoor City’s woodlands, imagine you’re following a herd of ‘megafauna’. Mammoths, for example.

“We look at landscape management these days in terms of the megafauna before humanity arrived,” said city council ecologist Angus Hunter.

“They’d be wandering through the woods trashing the place, and then moving on.”

Woodland partly cleared to attract willow tits in Ecclesall Woods

So a recent job for two of the city’s woodland rangers and a herd of 14 volunteers was to act like ancient big British beasts for the day, by selectively ‘trashing’ a small patch of Ecclesall Woods, all to benefit a little greyish bird depicted by Gilbert and Sullivan as the self-destructive ‘tit willow’.

The operettists might have been onto something. Ranger (and part time mammoth) Matt Coster noted that the willow tit builds its nest by carefully excavating a narrow chamber behind a hole in dead wood about a metre off the ground (within urban cat catching range), and then chatters incessantly attracting other predators like woodpeckers as its babies are reared. And to cap it off, they ‘stack’ the chicks on top of each another in the narrow nest chamber.

“They do themselves no favours at all,” Matt said.

Nevertheless, the willow tit survived for millennia in wettish British woodlands until around forty years ago.

“They’re now one of the fastest declining birds in the UK, with a 90% fall in numbers since the 1970s,” said Angus Hunter. “They’re dropping through the floor, and no-one really knows why.”

The booming numbers of blue and great tits are implicated, since they evict less aggressive willow tits from their new self-builds, which are ideal for birds who can’t be bothered to dig out their own nest chambers. But the loss of connected corridors of wet woodlands, with enough sunlight to allow a good layer of undergrowth, seems the most important reason for the decline.

Friends of Ecclesall Woods volunteer ring barking a tree to create dead wood for wildlife

Which is where megafauna-based conservation work comes in. The city council and local groups including the Steel Valley Project, Sheffield and Rotherham Wildlife Trust, the Friends of Ecclesall Woods and the Sheffield Bird Study Group have got together to help the endangered bird by identifying existing and potential nest sites, and then clearing certain trees, like birch, holly and sycamore, to create dead wood and allow light and undergrowth to return.

Earlier this year, council ranger Chris Roberts designed a prototype willow tit nest box, by excavating the inside of a felled log, patching it back up to look like a dead birch tree, and then painstakingly reinserting the chippings behind a small and inviting hole entrance. It worked immediately.

The ‘Roberts’ nest box being used by a willow tit in north Sheffield. Photo: Richard Gill

“I watched them excavating their nest, and then saw a massive fight when some blue tits heard them and went in the hole. It was unbelievable, they were all falling into the leaves claws out wings flapping, but the blue tits won.”

Luckily, Chris had attached two more nest logs to nearby trees in the north Sheffield woodland, and the willow tits excavated a second and laid seven eggs, which unfortunately didn’t hatch — probably because at least one of the parent birds had been snatched by a predator, Chris said. “But it looks as if the design is suitable.”

Sheffield will be the proud host of a national ‘Willow Tit Summit’ next month, when volunteers and professionals from around the north of England will swap ideas to try and save the bird.

“Sheffield should be clapping ourselves, with organisations doing fabulous stuff around this area,” said Chris Roberts.

For example, Matt mentioned a group of ex-miners from Barnsley whose careful monitoring for thirty years showed that a good layer of brambles increases the chance of nest success.

There are patchy willow tit populations around the city in Stocksbridge, Rother Valley, Holbrook, Dore and Gleadless Valley, but it’s hoped using the new nest log, combined with ‘trashing’ patches of woodland like bison, rhinos or elephants would have done many years ago, will allow the birds to extend their range into new areas of wet woods where there are brambles, patches of sunlight, dead wood and grasses to feed on.

Matt said new volunteers are always welcome, and wild garden owners might have a chance too if there were willow tits nearby — as long as they have a few brambles and wild grasses. If a mammoth dropped in now and then too, all the better.

To volunteer call: 0114 250 0500

Willow tit fledgling being fed by a parent. Photo: Robert Croxton